/*
 * Copyright (c) 2002, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.parser;

import static com.sun.tools.javac.parser.Token.IDENTIFIER;

import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.Log;
import com.sun.tools.javac.util.Name;

/**
 * Map from Name to Token and Token to String.
 * 
 * <p>
 * <b>This is NOT part of any supported API. If you write code that depends on
 * this, you do so at your own risk. This code and its internal interfaces are
 * subject to change or deletion without notice.</b>
 */
public class Keywords {
	public static final Context.Key<Keywords> keywordsKey = new Context.Key<Keywords>();

	public static Keywords instance(Context context) {
		Keywords instance = context.get(keywordsKey);
		if (instance == null)
			instance = new Keywords(context);
		return instance;
	}

	private final Log log;
	private final Name.Table names;

	protected Keywords(Context context) {
		context.put(keywordsKey, this);
		log = Log.instance(context);
		names = Name.Table.instance(context);

		for (Token t : Token.values()) {
			if (t.name != null)
				enterKeyword(t.name, t);
			else
				tokenName[t.ordinal()] = null;
		}

		key = new Token[maxKey + 1];
		for (int i = 0; i <= maxKey; i++)
			key[i] = IDENTIFIER;
		for (Token t : Token.values()) {
			if (t.name != null)
				key[tokenName[t.ordinal()].index] = t;
		}
	}

	public Token key(Name name) {
		return (name.index > maxKey) ? IDENTIFIER : key[name.index];
	}

	/**
	 * Keyword array. Maps name indices to Token.
	 */
	private final Token[] key;

	/**
	 * The number of the last entered keyword.
	 */
	private int maxKey = 0;

	/**
	 * The names of all tokens.
	 */
	private Name[] tokenName = new Name[Token.values().length];

	@SuppressWarnings("static-access")
	public String token2string(Token token) {
		switch (token) {
		case IDENTIFIER:
			return log.getLocalizedString("token.identifier");
		case CHARLITERAL:
			return log.getLocalizedString("token.character");
		case STRINGLITERAL:
			return log.getLocalizedString("token.string");
		case INTLITERAL:
			return log.getLocalizedString("token.integer");
		case LONGLITERAL:
			return log.getLocalizedString("token.long-integer");
		case FLOATLITERAL:
			return log.getLocalizedString("token.float");
		case DOUBLELITERAL:
			return log.getLocalizedString("token.double");
		case ERROR:
			return log.getLocalizedString("token.bad-symbol");
		case EOF:
			return log.getLocalizedString("token.end-of-input");
		case DOT:
		case COMMA:
		case SEMI:
		case LPAREN:
		case RPAREN:
		case LBRACKET:
		case RBRACKET:
		case LBRACE:
		case RBRACE:
			return "'" + token.name + "'";
		default:
			return token.name;
		}
	}

	private void enterKeyword(String s, Token token) {
		Name n = names.fromString(s);
		tokenName[token.ordinal()] = n;
		if (n.index > maxKey)
			maxKey = n.index;
	}
}
